Systems and methods for treatment of intervertebral disc derangements

ABSTRACT

Various embodiments provide systems and methods for repairing or replacing intervertebral discs as a treatment for derangements. Systems and methods may comprise an intervertebral disc implant for deployment into an intervertebral disc space wherein the nucleus has been at least partially evacuated from the deranged intervertebral disc. The intervertebral disc implant may be intraoperatively and postoperatively filled and/or re-filled with a growth matrix. The intervertebral disc implant may be differentially permeable to the growth matrix to provide directional growth and/or diffusion of the growth matrix to restore height to the intervertebral disc space. Systems and methods may further comprise an implant delivery device for deploying the intervertebral disc implant into the intervertebral disc space.

BACKGROUND

Intervertebral discs comprise a highly organized matrix of collagen,water, and proteoglycans produced by differentiated chondrocytes. Eachintervertebral discs comprises a central highly hydrated and gelatinousnucleus pulposus (nucleus) surrounded by an elastic and highly fibrousannulus fibrosus (annulus). Cartilaginous endplates provide a connectionto the vertebrae inferiorly and superiorly to the intervertebral disc.This cushioned arrangement within the intervertebral discs allows thediscs to facilitate movement and flexibility within the spine whiledissipating hydraulic pressure through the spine.

Intervertebral discs are susceptible to a variety of derangements fromdegenerative disease and traumatic injury that may result in molecularand morphological changes that affect the macromolecular structure ofthe disc. These derangements may cause an at least partial collapse anda loss of height of the intervertebral disc with consequent compressionof spinal nerves and pain. For example, degenerative disc disease mayoccur as an age-related process in which the nucleus changes from agelatinous material with high water content to a more fibrous,water-depleted material that may form fissures and/or tears. Thedegenerated nucleus may exhibit a decreased ability to evenly distributehydraulic pressure from the compression of the spine through theintervertebral disc and may prolapse into the surrounding annulus.Degenerative disc disease may also result in tearing of the vertebralendplates and/or the annulus tissue, causing the nucleus to herniatethrough the fibers of the annulus to compress spinal nerve roots andcause pain.

Derangements of the intervertebral disc may cause severe back pain,spasms of back muscles, muscle weakness in the legs, numbness in the legand/or foot, radiating pain down the leg, and changes in bladder and/orbowel function. Pain from intervertebral disc derangements may beintractable and debilitating. Pain may be improved for some patientswith physical therapy, modification of activity, and/or medication.Patients that fail to respond to noninvasive interventions for backpain, however, may require surgery on the damaged intervertebral disc.

A variety of surgical interventions may be employed to relieve nervepressure and pain. For example, one possible treatment may comprise adiscectomy wherein a herniated portion of the intervertebral disc isremoved. In another procedure, a laminectomy may be performed to removea portion of the lamina to enlarge the spinal canal and relieve nervepressure. In a spinal fusion procedure, two or more vertebrae may bepermanently fused in the area of the damaged disc to eliminatecompression of the damaged disc caused by motion.

Surgical intervention for intervertebral disc derangements may alsocomprise replacing the damaged disc with an artificial disc in anarthroplasty surgery. Arthroplasty may be preferred to a spinal fusionprocedure in some patients because the artificial disc is intended torestore and preserve the native biomechanics of the intervertebral disc,such as providing the requisite cushion to the adjacent vertebra,supporting unrestricted motion of the spine, and reducing or preventingthe degeneration of adjacent intervertebral discs, which may be damagedafter fusion surgeries due to the permanently altered motioncharacteristics of the spine in the fused area.

An artificial disc may comprise a variety of biocompatible materials.For example, one type of artificial disc comprises a slidingpolyethylene core sandwiched between cobalt chromium alloy endplates.Adverse complications associated with artificial discs include discmigration causing nerve compression which requires revision surgery,degeneration of discs at another level of the spine, subsidence of theartificial discs, facet joint arthrosis, and wear of the polyethylene inthe artificial disc. Measures to correct these problems may require asubsequent surgery for removal of the artificial disc and fusion of theaffected vertebrae.

BRIEF SUMMARY

Various embodiments provide systems and methods for repairing orreplacing intervertebral discs as a treatment for derangements. Systemsand methods may comprise an intervertebral disc implant for deploymentinto an intervertebral disc space wherein the nucleus has been at leastpartially evacuated from the deranged intervertebral disc. Theintervertebral disc implant may be capable of intraoperative andpostoperative filling and/or re-filling with a growth matrix. Variousregions of the intervertebral disc implant may be differentiallypermeable to the growth matrix to provide directional growth and/ordiffusion of the growth matrix to restore height to the intervertebraldisc space. Systems and methods may further comprise an implant deliverydevice for deploying the intervertebral disc implant into theintervertebral disc space.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of the present technology may be derivedby referring to the detailed description when considered in connectionwith the following illustrative figures. In the following figures, likereference numbers refer to similar elements and steps throughout thefigures.

Elements and steps in the figures are illustrated for simplicity andclarity and have not necessarily been rendered according to anyparticular sequence or scale. For example, steps that may be performedconcurrently or in different order are illustrated in the figures tohelp to improve understanding of embodiments of the present technology.

The figures described are for illustration purposes only and are notintended to limit the scope of the present disclosure in any way.Various aspects of the present technology may be more fully understoodfrom the detailed description and the accompanying drawing figures,wherein:

FIGS. 1A-1B representatively illustrate side views of exemplary inflatedintervertebral disc implants;

FIG. 2 representatively illustrates a superior (top) view of anexemplary intervertebral disc implant;

FIGS. 3A-3B representatively illustrate a side and superior view,respectively, of an exemplary spiral-form intervertebral disc implant;

FIG. 4 representatively illustrates a side view of an exemplaryintervertebral disc implant in a deflated state;

FIGS. 5A-J representatively illustrate an exemplary method for deployingan intervertebral disc implant into an intervertebral disc spacecomprising a deranged intervertebral disc;

FIGS. 6A-E representatively illustrate an exemplary method for deployingan intervertebral disc implant into an intervertebral disc space;

FIGS. 7A-E representatively illustrate an exemplary method for restoringheight to the intervertebral disc space prior to deployment of anintervertebral disc implant;

FIGS. 8A-D representatively illustrate a method for implanting aspiral-form intervertebral disc implant into an intervertebral discspace comprising a deranged intervertebral disc;

FIG. 9 representatively illustrates an exemplary intervertebral discimplant deployed into a knee joint;

FIG. 10 representatively illustrates a side view of an exemplaryintervertebral disc implant comprising a nutrient capsule;

FIGS. 11A-C representatively illustrate an exemplary delivery device fordeploying an intervertebral disc implant into an intervertebral discspace. and

FIG. 12 representatively illustrates a side view of an exemplaryintervertebral disc implant with pores distributed in a gradient.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present technology may be described in terms of functional blockcomponents and various processing steps. Such functional blocks may berealized by any number of components configured to perform the specifiedfunctions and achieve the various results. For example, the presenttechnology may employ various materials, fill material, growth media,delivery and/or deployment systems, etc. In addition, the presenttechnology may be practiced in conjunction with any number of systemsand methods for intervertebral disc repair and/or replacement, and thesystem described is merely one exemplary application for the invention.

The particular implementations shown and described are illustrative ofthe invention and its best mode and are not intended to otherwise limitthe scope of the present technology in any way. For the sake of brevity,conventional manufacturing, connection, preparation, sterilization, andother functional aspects of the system may not be described in detail.Furthermore, the connecting lines shown in the various figures areintended to represent exemplary functional relationships and/or stepsbetween the various elements. Many alternative or additional functionalrelationships or physical connections may be present in a practicalsystem.

Various embodiments of the invention provide methods, apparatus, andsystems for making an intervertebral disc implant, including anintradiscal implant, and a delivery device for surgical deployment ofthe intervertebral disc implant into an intervertebral disc space, suchas within a partially excised intervertebral disc or in a fully orpartially evacuated disc space. A detailed description of variousembodiments is provided as a specific enabling disclosure that may begeneralized to any application of the disclosed systems and methods inaccordance with the various described embodiments.

Various representative implementations of the present technology may beapplied to any system for intervertebral disc repair, healing, and/orreplacement. Certain representative implementations may include, forexample, providing any suitable system or method for restoring height toa compressed intervertebral disc space. In some embodiments, the systemor method may comprise an intervertebral disc implant system. Forexample, intervertebral disc implant may comprise an intradiscal implantfor deployment into the intervertebral disc space. At the time ofdeployment, the intervertebral disc space may contain a degeneratedintervertebral disc, a partially evacuated intervertebral disc such aswhere the nucleus pulposus has been surgically removed, and/or an emptyintervertebral disc space wherein the intervertebral disc has beenremoved.

In various embodiments, the intervertebral disc implant may comprise anexpandable pouch. The expandable pouch may comprise a pouch walldefining a lumen. The pouch wall may further comprise a delivery system,such as a plurality of pores, that may allow one or more components of afill material, such as a growth matrix, disposed within the lumen topermeate and be delivered into the intervertebral disc space. In someembodiments, the expandable pouch may function as a scaffolding in theformation of a structure in an expanding growth matrix. In variousembodiments, differences in the location, size, and/or chemicalstructure of the pores may provide directional permeation of the fillmaterial into the intervertebral disc space. In some embodiments, theexpandable pouch may be configured to be intraoperatively fillableand/or post-operatively refillable with the fill material afterdeployment of the intervertebral disc implant into the intervertebraldisc space. The directional movement of the fill material out of theexpandable pouch may increase the height of the intervertebral space.

In some embodiments, the intervertebral disc implant system may furthercomprise a delivery device for deploying the intervertebral disc implantinto the intervertebral disc space. In some embodiments, the deliverydevice may house and/or be coupled to the intervertebral disc implant.In various embodiments, the delivery device may deploy theintervertebral disc implant into the intervertebral disc space, such asthrough a trocar during surgery.

Referring to FIGS. 1A-B, exemplary embodiments of the intervertebraldisc implant 100 may comprise a deformable pouch configured to beinserted into the intervertebral space, such as an expandable pouch 105.The expandable pouch 105 may comprise a fill port, such as a valve 120and/or a fill diaphragm 135, like a self-sealing septum. The fill portfacilitates filling the expandable pouch 105 with a fill material. Insome embodiments, the fill port may provide postoperative access to thelumen of the expandable pouch for refilling with the fill material. Inone embodiment, the fill port is disposed through a posterior surface ofthe expandable pouch 105 and configured to provide access to a lumen 110(the interior cavity) of the expandable pouch 105. In variousembodiments, the expandable pouch 105 may be filled with the fillmaterial, such as the growth matrix or other fill material, through thevalve 120, such as by connection of the valve to access tubing (notshown).

In another embodiment, the expandable pouch 105 may be filled with thefill material through the fill diaphragm 135, such as by being piercedwith a needle intraoperatively. In some embodiments, the expandablepouch 105 may be post-operatively re-filled, such as through apercutaneous procedure in which access to the intervertebral discimplant 100 may be achieved through needle-puncture of the skin. Theexpandable pouch 105 may have an inflated height 125 that may varyaccording to the degree the expandable pouch 105 is filled with the fillmaterial.

Referring to FIG. 4, the expandable pouch 105 may have a collapsedheight 140. The collapsed height 140 may be shorter than the inflatedheight 125 to enable transit of the intervertebral disc implant 100through surgical instruments and/or an access opening surgically createdin the compressed intervertebral disc space. The expandable pouch 105may inflate, such as when filled with the fill material. The expandablepouch 105 may be adapted to have a pre-selected internal volume forfilling with fill material or the expandable pouch 105 may comprise amaterial with an elastic quality to allow over-distention with the fillmaterial.

Referring to FIGS. 3A-B, the intervertebral disc implant 100 may beconfigured for ease of insertion and deployment, such as in a spiralform (as shown in the superior view in FIG. 3A). In some embodiments ofthe spiral-form intervertebral disc implant 100, the expandable pouch105 may comprise a plurality of interconnected chambers 300. Theinterconnected chambers 300 may comprise a single, continuous piece ofthe expandable pouch 105. The interconnected chambers 300 may alsocomprise separate coupled segments of the expandable pouch 105. In boththe continuous and segmented embodiments of the expandable pouch 105,each chamber 300 may comprise a connection area 305 between eachadjacent chamber 300. The connection area 305 may comprise any opening,pore, membrane, connector, channel, or the like that may provide fluidcommunication between the chambers 300. The fill material may enter thefill port and propagate throughout the chambers 300. In one embodiment,the expandable pouch 105 may comprise a self-assembling modular materialwherein the chambers 300 assume the spiral-form upon delivery into theintervertebral disc space.

In an exemplary embodiment of the present technology, as shown in thesurgical delivery method illustrated in FIGS. 8A-D, the chambers 300 maycomprise a linear configuration as the intervertebral disc implant 100travels through a trocar-cannula 518 (FIG. 8A). The chambers 300 mayorganize into the spiral configuration upon delivery into anintervertebral disc space 560 (FIG. 8B). Once positioned in theintervertebral disc space 560, the fill material may propagate throughand/or grow out of the pores 105 in the intervertebral disc implant 100(FIG. 8C). As illustrated in the superior view of FIG. 8D, thespiral-form of the intervertebral disc implant 100 may occupy an atleast partially empty nucleus space 560.

The expandable pouch 105 may comprise any suitable material for formingan at least partially enclosed balloon-like sac. In various embodiments,the expandable pouch 105 may comprise a material that is biocompatible,biodegradable, dissolvable, and/or bioabsorbable material. Theexpandable pouch 105 may degrade, dissolve, and/or be absorbed by bodyfluids over time. The dissolution of the expandable pouch 105 may reduceor eliminate explantation or the need for revision surgery that mayarise from its migration within the intervertebral disc space.

In various exemplary embodiments, the expandable pouch 105 may comprisea polymer such as polyacrylate, polyvinylidene, polyvinyl chloridecopolymer, polyurethane, polystyrene, polyamide, cellulose acetate,cellulose nitrate, polysulfone, polyphosphazene, polyacrylonitrile,poly(acrylonitrile/covinyl chloride), polyglycolic acid (PGA),polylactic acid (PLA), polylactic-co-glycolic acid (PLGA),poly-ε-caprolactone (PCL), polydioxanone (PDO), a polyethylene,poly(glycerol sebacate) (PGS), or a derivative, copolymer or mixturethereof. In some embodiments, the expandable pouch 105 may comprise abiocompatible elastomeric material. In various embodiments, theexpandable pouch 105 may comprise a radiopaque material to allowvisualization of the intervertebral disc implant 100 using imagingtechniques during surgical implantation, post-operative needle insertioninto the intervertebral disc implant 100 for refilling with the fillingmaterial, and post-operative follow up for positioning of theintervertebral disc implant 100. For example, the radio opaque materialmay comprise radiopaque thermoplastic compounds, barium sulfate,bismuth, tungsten, and other radiopaque materials or combinationsthereof.

In various embodiments of the present technology, the expandable pouch105 may be configured to transfer material from the pouch 105 to theintervertebral space. For example, the expandable pouch 105 may comprisea delivery system for transferring fill material to the intervertebralspace, such as a plurality of pores 115 defined through the pouch 105material. The pores 115 may be arranged in any suitable manner acrossthe expandable pouch 105 to provide the desired repair and/orreplacement of the deranged intervertebral disc.

For example, in some embodiments, the pores 115 may be arranged todirect the permeation of the growth matrix primarily through thesuperior and/or inferior surfaces of the expandable pouch 105. Thesuperior and/or inferior permeation of the growth matrix into theintervertebral disc space may promote contact of the growth matrix withthe superior and inferior endplates adjacent to the derangedintervertebral disc, as opposed to lateral diffusion out of theintervertebral disc space. Contact with the endplates may in turnincrease the height of the compressed intervertebral disc space.

In various embodiments, the pores 115 in the expandable pouch 105 may bearranged in any suitable manner that may promote the directionalpermeation, diffusion, and/or growth of the fill material out of theintervertebral disc implant 100. In various embodiments, the pores 115may be arranged according to any pore parameters, such as one or more ofpore diameter, pore location, pore concentration, and pore lumenchemistry, such as hydrophobicity or hydrophilicity.

Referring to FIG. 12, In some embodiments, the pore parameter may bearranged as a gradient along one or more surfaces of the expandablepouch 105. For example, in one embodiment, the pore parameter may be adensity gradient of the pores 115 that may begin with the highestconcentration of pores 115 located primarily on the superior and/orinferior surface of the expandable pouch 105 and decrease inconcentration toward the lateral sides of the expandable pouch 105. Inanother embodiment, the pore parameter may be a gradient of the diametersuch that pores 115 having a larger diameter may be disposed on thesuperior and/or inferior surfaces of the expandable pouch 105 and pores115 having comparatively smaller diameters may be disposed on thelateral surfaces. In another embodiment, a sealant, such as Duraseal®,may be applied to some areas of the pores 115 to create one or morezones of permeability to the fill material and impede others.

In the exemplary embodiments shown in FIGS. 1A and 1B, the pores 115 maybe located on a superior and inferior surface of the expandable pouch105 with an absence of pores 115 along the lateral sides. In oneembodiment, as illustrated in FIG. 2, the pores 115 may be distributedsubstantially evenly across the superior and/or inferior portion of theexpandable pouch 105. In other embodiments, the pores 115 may bedistributed across the superior and/or inferior portion of theexpandable pouch 105 in any suitable pattern, such as a substantiallyregular pattern (as shown) and/or an irregular pattern (not shown).

In various embodiments of the present technology, strategic placement ofthe pores 115 on the superior and/or inferior surfaces of the expandablepouch 105 may facilitate the restoration of the height of theintervertebral disc space. For example, the pores may be selectivelyplaced to direct the permeation of the growth matrix toward thevertebral endplates that form the superior and inferior boundaries ofthe intervertebral disc space. In some embodiments, lateral surfaces ofthe expandable pouch 105 may be less permeable than at least one of thesuperior surface and the inferior surface of the expandable pouch 105.In some embodiments, lateral surfaces of the expandable pouch 105 may besubstantially impermeable to the growth matrix. In one embodiment, theheight of the intervertebral disc space may be improved or restored ascomponents of the growth matrix, such as dividing cells as discussedbelow, proliferate through the pores 115 and establish a resilientstructure on the inferior and/or superior surfaces of the adjacentvertebrae.

In various embodiments of the present technology, the directionalpermeability of the intervertebral disc implant 100 may promote anincrease in the height of the intervertebral disc space withoutsubstantial changes in its width and/or depth. For example, deploymentof the intervertebral disc implant 100 into an annulus where thenucleus, or portion thereof, has been removed may result in a naturalborder for the intervertebral disc implant 100. The natural border maycomprise the inferior endplate of the superior vertebra, the superiorendplate of the inferior vertebra, and the lateral borders of theannulus. Filling and distension of the expandable pouch 105 with thegrowth matrix and subsequent permeation, diffusion, and/or growth of thegrowth matrix may be substantially confined by these natural borders.The embodiments of the expandable pouch 105 wherein the distribution ofthe pores 115 provide permeability across at least one of the superiorsurface and the inferior surface of the expandable pouch 105 andcomparatively less permeability across the lateral surfaces of theexpandable pouch 105 may further promote the restoration of height ofthe intervertebral disc space. As a result, the directional permeabilityprovided by the arrangement of the pores 115 in the expandable pouch 105may increase the height of the intervertebral disc without a detrimentalincrease in disc circumference.

The pores 115 may be created in the expandable pouch 105 through anysuitable process. In some embodiments, expandable pouch 105 may becreated in a mold defining pores, such as a mold used during curing ofthe expandable pouch 105. In one embodiment, the pores 115 may becreated with conventional stamping methods, compression of large poresinto comparatively smaller pores of a desired diameter, chemicaletching, and/or bombardment methods such as laser irradiation and/or ionirradiation. In various embodiments, the pores 115 may be created on ananometric to micrometric scale. For example, the pores 115 may have adiameter of approximately 10 μm to promote diffusion and/or growth ofthe growth matrix through the pores 115.

Referring again to FIGS. 1A and 1B, in various embodiments of thepresent technology, the height 125 of the intervertebral disc implant100 in a fully inflated state may be approximately the desired height ofan intervertebral disc space between two adjacent vertebrae.Additionally, the length 130 of the intervertebral disc implant 100 in afully inflated state may be approximately the length of theintervertebral disc. Accordingly, the intervertebral disc implant 100may be provided in a variety of heights 125, lengths 130, and otherconfiguration aspects to accommodate variations between patients. Forexample, a particular size of intervertebral disc implant 100 may beused for patients based on gender, height, age, and/or ethnicity. Thelocation of the damaged intervertebral disc in the low lumbar, higherlumbar, thoracic, or cervical spine may also influence the configurationof the intervertebral disc implant 100.

The desired height 125, width, and/or length 130 of the intervertebraldisc implant 100 may be determined intraoperatively by a surgeon basedon the patient's anatomy using imaging information, such as computedtomography (CT) imaging information or other imaging studies, of thepatient's vertebrae and intervertebral discs. For example, in oneexemplary embodiment, the intervertebral disc implant 100 may beconfigured to fit in the at least partially evacuated nucleus space ofan intervertebral disc. In some embodiments, the inflated intervertebraldisc implant may be at least approximately 1 inch long, at leastapproximately 0.5 inches wide, and at least approximately 0.25 inches inheight. In some embodiments, the inflated intervertebral disc implant100 may be may be approximately up to 2 inches long by up to 1.5 incheswide by up to 0.5 inches in height to fit into the at least partiallyevacuated nucleus space. In some embodiments, the inflatedintervertebral disc implant 100 may be approximately 1-2 inches long,0.5-1 inches wide, and/or 0.25-0.5 inches in height.

Based upon the surgeon's intraoperative assessment of the volume of theat least partially evacuated nucleus space, a fill volume for theexpandable pouch 105 may be selected. The intervertebral disc implant100 may be filled with the fill material up to a maximum fill volumeresulting in the height 125 or may be underfilled to an amount less thanthe maximum fill volume to accommodate differences in the intervertebraldisc space in different patients or within the vertebrae of the samepatient. For example, in one embodiment, the intervertebral disc implant100 may be filled within a range of approximately 0.5 cc to 5 cc of fillmaterial.

Referring to FIG. 4, an empty intervertebral disc implant 100 may be inan at least partially collapsed state and may have a height 140 that maybe shorter than the height 125 of an at least partially to fullyinflated intervertebral disc implant 100. In one embodiment, the height140 may be adapted to allow the intervertebral disc implant 100 to fitthrough an inner opening of a trocar-cannula tool for surgicalimplantation. For example, the intervertebral disc implant 100 may fitthrough the trocar-cannula wherein the diameter of the inner opening isless than approximately 20 millimeters. In some embodiments, thediameter of the trocar-cannula's inner opening may be approximately 5millimeters or less. In various embodiments, the height of the deflatedintervertebral disc implant 100 may be equal to or less than thediameter of the inner opening of the trocar-cannula used to surgicallyintroduce the intervertebral disc implant 100 into the intervertebraldisc space. In various embodiments of the present technology, theintervertebral disc implant 100 may be filled with the fill materialthrough a fill port, such as a valve 120 or a fill diaphragm 135. Thefill port may be located on any suitable surface of the intervertebraldisc implant 100 such that the fill material may be inserted into thelumen 110, such as injection after implantation into the intervertebraldisc space. In one embodiment, the fill port may be a discrete injectionsite on a posterior-lateral or side surface of the intervertebral discimplant 100 to orient the injection site. Such orientation mayfacilitate intra-operative filling and/or post-surgical re-filling ofthe intervertebral disc implant 100. In some embodiments, the fill portmay include the fill diaphragm 135 comprising a suitable biocompatibleself-sealing injection material, such as rubber or silicone. In anotherembodiment, the fill port may comprise the valve 120 or other devicethat may be connected to a fill tube (not shown).

In various embodiments of the present technology, the intervertebraldisc implant 100 may be placed into the intervertebral disc space usinga delivery device. For example, the delivery device may comprise asuitable rod or cannula that may be coupled to and/or at least partiallyhouse the intervertebral disc implant 100. The delivery device may becoupled to the intervertebral disc implant 100 with any suitableconnector, such as a snap, adhesive, clamp, clip, and the like that maybe mechanically uncoupled (such as with a twist and/or pop of thedelivery device to dissociate from the intervertebral disc implant 100)and/or chemically uncoupled after implantation of the intervertebraldisc implant 100 into the intervertebral disc space. In someembodiments, the delivery device may comprise a tube or needleconfigured to fill the intervertebral disc implant 100 with the fillmaterial during and/or after deployment of the intervertebral discimplant 100 into the intervertebral disc space. In various embodiments,the delivery device may be configured to pass through thetrocar-cannula, implant the intervertebral disc implant 100 into theintervertebral space, uncouple from the intervertebral disc implant 100,withdraw from the intervertebral space, and be removed from thetrocar-cannula.

Referring to FIGS. 11A-C, an exemplary delivery device 1100 may comprisean introducer tool 1105. The introducer tool 1105 may comprise a handleconfigured to be coupled to a delivery cannula 522. The introducer tool1105 may be used to push the delivery cannula 522 through thetrocar-cannula (not shown) and into the intervertebral disc space. Theintroducer tool 1105 and delivery cannula 522 of the delivery device1100 may be configured to travel through a trocar to reach theintervertebral disc space having a diameter that is equal to or smallerthan the inner diameter of the trocar-cannula, such as less than 20millimeters in diameter. The introducer tool 1105 may comprise anysuitable mechanism, such as a switch, trigger, button, or release forthe surgeon to control the attachment of the delivery cannula 522 to theintervertebral disc implant 100.

For example, in one embodiment, the delivery cannula 522 may comprise afastener 1110 that may be coupled to the valve 120 for positioning theintervertebral disc implant 100 in the intervertebral space. Thefastener 1110 may dissociate from the valve 120, as shown in FIG. 11C,leaving the intact intervertebral disc implant 100 behind in theintervertebral space. In some embodiments, as shown in FIG. 11B, thedelivery device 1100 may further comprise or be configured to accept aneedle 1115 for operating the fill port to fill the intervertebral discimplant 100 with the fill material.

In various embodiments of the present technology, the fill material mayinclude therapeutic materials to be exposed to the surrounding tissue,such as a growth matrix. The growth matrix may comprise any materialthat may comprise a biological material and/or any material that maysupport, or augment, regulate, propagate, or otherwise sustain thegrowth of the biological material. For example, the biological materialmay comprise cells and/or tissue that may provide restoration of heightto the intervertebral disc space as the biological material grows and/ordiffuses through the pores 115 of the intervertebral disc implant 100.In various embodiments, the growth matrix may comprise one or more ofcells or tissue such as stem cells and/or chondrocytes, cellular matrixmaterials such as biopolymers or other scaffolding materials,nutritional media, and/or additives such as growth and/ordifferentiation factors. In one embodiment, the components of the growthmatrix comprising cells or tissue, cellular matrix material, and/oradditives may be commixed in vitro prior to injection into theintervertebral disc implant 100. In another embodiment, the growthmatrix may be aerated with a gas optimized for cell growth prior toinjection into the intervertebral disc implant 100. Ultimately,nutrition and gas exchange may be supplied by diffusion from nearbyblood vessels to the cells or tissue of the growth matrix.

In some embodiments, the cellular matrix materials may comprise asupportive scaffold structure for the cells and/or tissue to divide andform three-dimensional tissue structures. In one embodiment, theresultant tissue structure may function as a prosthetic intervertebraldisc. In various embodiments, some components of the cellular matrixmaterials may be non-toxic, biocompatible, and/or biodegradable. Forexample, the cellular matrix material may comprise biodegradablebiopolymers including organic polymers such as polyglycolic acid (PGA),polylactic-co-glycolic acid (PLGA), poly-ε-caprolactone (PCL), polyaminoacids, polyanhydrides, and/or polyorthoesters. The biodegradeablebiopolymers may also comprise natural hydrogels such as collagen,hyaluronic acid, alginate, agarose, and/or chitosan. Additionally, thebiodegradeable biopolymers may comprise synthetic hydrogels such aspoly(ethylene oxide) (PEO), poly(vinyl alcohol) (PVA), poly(acrylicacid) (PAA), poly(propylene fumarate-co-ethylene glycol) [P(PF-co-EG)],and/or copolymers thereof.

In various embodiments, the growth matrix may comprise any additivesneeded for propagation of the cells or tissue. For example, theadditives may comprise a nutritional medium for supplying a carbohydratesource, supplements, vitamins, minerals, growth factors, differentiationfactors, hormones, attachment factors, and/or salts to promote viabilityof the cells and/or tissue. In some embodiments, the additives includingnutritional media may be at least partly a solid, liquid, and/or a gel.

Referring to FIG. 10, in various embodiments of the present technology,the intervertebral disc implant 100 may comprise a nutrient capsule1002. The nutrient capsule 1002 may comprise one or more additives thatare disposed in a controlled release capsule and/or gel system. In oneembodiment, the nutrient capsule may be a cellulose derivative polymersuch as hydroxypropylmethylcellulose (e.g., Methocel®) wherein theadditive wets and hydrates the cellulose and slowly diffuses out of thecellulose into the lumen 110 of the intervertebral disc implant 100. Theslow release of the additives may provide additional nutrition andgrowth factors to support the propagation of the cells and/or tissueafter the additives provided in the lumen 110 of the intervertebral discimplant 100 are consumed.

In operation, the intervertebral disc implant 100 may be surgicallyintroduced into the intervertebral disc space using the delivery deviceinserted through the trocar-cannula. An exemplary method of deployingthe intervertebral disc implant 100 into the intervertebral disc spaceis illustrated in a lateral view shown in FIGS. 5A-J and a superior viewshown in FIGS. 6A-E. A portion of a spine 500 may comprise a healthyintervertebral disc 510 that maintains a normal intervertebral discspace height 526 between vertebral body 512 and vertebral body 508,providing spinal flexibility (see FIG. 5A). As shown in FIG. 6A, thehealthy intervertebral disc 510 comprises an annulus 606 and a hydratedhealthy nucleus 604.

The spine 500 may also comprise a deranged intervertebral disc 506. Asillustrated in the superior view shown in FIG. 6B, the derangedintervertebral disc 506 may comprise an annulus 606 and a dehydratednucleus 602. The deranged intervertebral disc 506 may comprise anynumber of other derangements including, but not limited to, aprotrusion/herniation 604 as shown in FIG. 6B and/or degenerative discdisease that may result in the compression and/or loss of elasticity ofthe deranged intervertebral disc 506. The deranged intervertebral disc506 may result in a compressed intervertebral disc space height 528between vertebral body 502 and vertebral body 512.

As illustrated in FIGS. 5A-J, the deranged intervertebral disc 506 maycomprise an annular tear 555 (FIGS. 5A, 5B). Diffusion and growth of thegrowth matrix from the intervertebral disc implant 100 deployed into thederanged intervertebral disc 506 may promote at least partial repair ofthe annular tear 555. At least partial repair of the annular tear 555may reduce chemical leaks out of the intervertebral disc space 516. Suchleaks may irritate nerves (not shown) in the vertebral foramen (600 ofFIG. 6A) and cause back pain and/or radicular pain.

Deployment of the intervertebral disc implant 100 into the derangedintervertebral disc 506 to at least partially repair the derangement maybe performed in any suitable surgical procedure such as conventionalarthroplasty surgery or a transpedicular discectomy. The surgicalprocedure may be an open procedure, a minimally invasive image-guidedprocedure (such as fluoroscopically or x-ray guided), or endoscopicallyas guided by a camera. Generally, a trocar comprising an obturator 514and a trocar-cannula 518 may provide an access port to the derangedintervertebral disc 506 (FIG. 5B). As shown in FIGS. 5A and 5B and FIGS.6C-D, the obturator 514 and trocar-cannula 518 may be inserted from aminimally invasive posterior lateral position to access theintervertebral disc 506, bypassing the vertebral foramen 600 (shown inFIGS. 6C and 6D). Access to the deranged intervertebral disc 506 mayalso be performed in laparoscopic anterior spine surgery through theabdomen or in a lateral fashion with the patient on his or her sidewhich may avoid the major muscles of the back (methods not shown). Thetrocar-cannula 518 may be slipped over the obturator 514 to provide ahollow access tube that reaches the deranged intervertebral disc 506(FIG. 5B).

The obturator 514 may be withdrawn and a cutting cannula 520 may beinserted into the trocar-cannula 518 (FIG. 5C). The cutting cannula 520may at least partially remove the dehydrated nucleus 608 through thetrocar-cannula 518 leaving an at least partially empty nucleus space 560(see FIGS. 5C and 5D, and FIG. 6C). The cutting cannula 520 may then beremoved from the trocar-cannula 518 (FIG. 5D).

In some embodiments of the method for deploying the intervertebral discimplant 100 into the nucleus space 560, the delivery cannula 524 of thedelivery device 1100 may be coupled to the at least partially deflatedintervertebral disc implant 100 and inserted into the trocar-cannula 518(FIG. 5E). The at least partially deflated intervertebral disc implant100 may be advanced through the trocar-cannula 518 and deployed into thenucleus space 560 (FIG. 5F). Upon placement in the nucleus space 560,the intervertebral disc implant 100 may be filled intraoperatively to adesired volume with the growth matrix, such as through the needle 1115(not shown) (FIG. 5G).

The growth matrix may begin directional diffusion and/or directionalgrowth out of the intervertebral disc implant 100 into theintervertebral disc space 516. As a result, the height 528 of theintervertebral disc space 516 may be intraoperatively and/or graduallypostoperatively restored to a height similar to the normalintervertebral disc space height 526, relieving the patient's spinalpain. After successful placement and filling of the intervertebral discimplant 100, the delivery cannula 522 may be uncoupled from theintervertebral disc implant 100 and removed from the trocar-cannula 518(not shown). Finally, the trocar-cannula 518 may be removed from theintervertebral disc space 516 to end the surgery (FIG. 5H).

As shown in FIGS. 7A-E, in another method for deploying theintervertebral disc implant 100 into the nucleus space 560, the height528 of the intervertebral disc space 516 may be expanded prior todeployment of the intervertebral disc implant 100 using a suitableorthopaedic balloon system 702/704. For example, the orthopaedic balloonsystem 702/704 may be the same as or similar to that used in balloonkyphoplasty procedures for repairing vertebral compression fractures,such as a Kyphon® Balloon (Medtronic Spinal and Biologics, Sunnyvale,Calif.). Generally, a deflated orthopaedic balloon 702 may be guidedthrough the trocar-cannula 518 into the intervertebral space 516 (FIGS.7A and 7B). The orthopaedic balloon 702 may then be at least partiallyinflated with air or an appropriate liquid, such as a sterile salinesolution, to increase the intervertebral disc space height 528 (FIG.7C). The orthopaedic balloon 702 may then be deflated and removed fromthe intervertebral space 516 and the trocar-cannula 518 (FIG. 7D). Afterremoval of the orthopaedic balloon, the delivery cannula 524 may then beinserted into the trocar-cannula 518. After expansion of theintervertebral disc space height 528, the intervertebral disc implant100 may be deployed into the nucleus space 560 as shown in FIG. 5 (FIG.7E).

In some embodiments of the present technology, the fill material may beadded to the intervertebral disc implant 100 post-operatively. Forexample, referring to FIG. 5I, the growth matrix and/or the additive maybe added to the intervertebral disc implant 100 through a needle 530inserted into the patient's skin and guided into the valve 120 and/orthe self-sealing septum 135. In some embodiments, the needle 530 may beinserted into the valve 120 and/or the self-sealing septum in afluoroscopically, x-ray, or other image-guided procedure.

In various embodiments of the present technology, the expandable pouch105 of the intervertebral disc implant 100 may at least partiallydissolve in the intervertebral disc space 516 (FIG. 5J). As theexpandable pouch 105 dissolves, the growth matrix in the lumen 110 maybe exposed to the intervertebral disc space 516. As a result, the growthmatrix may become more firmly attached within the natural borders of theintervertebral disc space 516.

In the foregoing description, the invention has been described withreference to specific exemplary embodiments. Various modifications andchanges may be made, however, without departing from the scope of thepresent technology as set forth. The description and figures are to beregarded in an illustrative manner, rather than a restrictive one andall such modifications are intended to be included within the scope ofthe present technology. Accordingly, the scope of the invention shouldbe determined by the generic embodiments described and their legalequivalents rather than by merely the specific examples described above.For example, the steps recited in any method or process embodiment maybe executed in any appropriate order and are not limited to the explicitorder presented in the specific examples. Additionally, the componentsand/or elements recited in any system embodiment may be combined in avariety of permutations to produce substantially the same result as thepresent technology and are accordingly not limited to the specificconfiguration recited in the specific examples.

Benefits, other advantages and solutions to problems have been describedabove with regard to particular embodiments. Any benefit, advantage,solution to problems or any element that may cause any particularbenefit, advantage or solution to occur or to become more pronounced,however, is not to be construed as a critical, required, or essentialfeature or component.

The terms “comprises,” “comprising,” or any variation thereof, areintended to reference a non-exclusive inclusion, such that a process,method, article, composition, system, or apparatus that comprises a listof elements does not include only those elements recited, but may alsoinclude other elements not expressly listed or inherent to such process,method, article, composition, system, or apparatus. Other combinationsand/or modifications of the above-described structures, arrangements,applications, proportions, elements, materials, or components used inthe practice of the present technology, in addition to those notspecifically recited, may be varied or otherwise particularly adapted tospecific environments, manufacturing specifications, design parameters,or other operating requirements without departing from the generalprinciples of the same.

The present technology has been described above with reference toexemplary embodiments. Changes and modifications may be made to theexemplary embodiments, however, without departing from the scope of thepresent technology. These and other changes or modifications areintended to be included within the scope of the present technology.

What is claimed is:
 1. A system for at least partially restoring heightof a compressed intervertebral disc space and healing a derangedintervertebral disc between a superior vertebra and an inferior vertebrain a spine, comprising: a growth matrix; and an intervertebral discimplant configured to at least one of repair and replace the derangedintervertebral disc to facilitate movement and flexibility within thespine, the intervertebral disc implant, comprising: an expandable pouchcomprising: a pouch wall at least partially permeable to the growthmatrix that defines a lumen, wherein: a first portion of the pouch wallis permeable to the growth matrix across at least one of a superiorsurface and an inferior surface of the expandable pouch, wherein thefirst portion of the pouch wall comprises a plurality of pores permeableto the growth matrix, wherein the distribution of pores across theexpandable pouch directs permeation of the growth matrix into theintervertebral disc space toward at least one of the superior vertebraand the inferior vertebra; a second portion of the pouch wall is lesspermeable to the growth matrix across a lateral surface of theexpandable pouch than the at least one of the superior surface and theinferior surface; and the first portion and the second portion of thepouch wall are both made of the same material which dissolves in theintervertebral disc space; and wherein the intervertebral disc implantprovides movement and flexibility to the spine where the intervertebraldisc implant is placed between the superior vertebra and the inferiorvertebra and after the intervertebral disc implant is filled with thegrowth matrix.
 2. The system of claim 1, wherein the second portion ofthe pouch wall is substantially impermeable to the growth matrix.
 3. Thesystem of claim 1, wherein the expandable pouch further comprises a fillport disposed through a posterior surface of the expandable pouch,wherein the fill port provides access to the lumen of the expandablepouch for filing with the growth matrix.
 4. The system of claim 3,wherein the fill port is configured to provide postoperative access tothe lumen of the expandable pouch for refilling with the growth matrix.5. The system of claim 1, wherein the expandable pouch is deflatable tofit inside a surgical trocar-cannula having an inner diameter of lessthan approximately 20 millimeters.
 6. The system of claim 1, wherein theexpandable pouch is at least one of partially inflated andover-distended upon filling with the growth matrix.
 7. The system ofclaim 1, wherein the expandable pouch comprises an at least partiallyself-assembling modular material configured to self-assemble into aspiral-form upon delivery into the intervertebral disc space.
 8. Thesystem of claim 7, wherein the at least partially modularself-assembling material comprises interconnected chambers.
 9. Thesystem of claim 1, wherein the expandable pouch further comprises aradiopaque material for imaging.
 10. The system of claim 1, furthercomprising: a delivery device for surgically implanting theintervertebral disc implant into the intervertebral disc space, whereinthe delivery device is configured to: couple to the intervertebral discimplant, insert the intervertebral disc implant into the intervertebraldisc space from a percutaneous position, and release the intervertebraldisc implant into the intervertebral disc space.
 11. The system of claim10, wherein the delivery device is further configured to travel througha trocar-cannula to reach the intervertebral disc space.
 12. The systemof claim 1, wherein the inflated intervertebral disc implantapproximates the size of a nucleus propulsus of the intervertebral disc.13. The system of claim 12, wherein the inflated intervertebral discimplant is at least approximately 1 inch long, at least approximately0.5 inches wide, and at least approximately 0.25 inches in height. 14.The system of claim 1, wherein the first portion allows the growthmatrix to at least one of diffuse and grow from the lumen of theexpandable pouch, out through the pores, and into the intervertebraldisc space.
 15. The system of claim 14, wherein the permeability of thefirst portion is effected by at least one of a diameter of a pluralityof pores and a chemical structure of the pores.
 16. The system of claim15, wherein the pores have a diameter of approximately 10 μm.
 17. Thesystem of claim 1, further comprising a nutrient capsule disposed withinthe lumen of the expandable pouch.
 18. The system of claim 1, whereindistribution of the pores is arranged in a gradient with the highestconcentration of pores located on the superior surface and the inferiorsurface and the concentration of pores decreasing according to thegradient toward the lateral surface of the expandable pouch resulting inless permeability across the lateral surface as compared to at least oneof the superior surface and the inferior surface.
 19. A system forsurgically repairing an intervertebral disc derangement in anintervertebral disc space between a superior vertebra and an inferiorvertebra in a spine, comprising: a growth matrix; an intervertebral discimplant configured to at least one of repair and replace the derangedintervertebral disc to facilitate movement and flexibility within thespine, wherein the intervertebral disc implant forms an expandable pouchthat dissolves in the intervertebral disc space, the intervertebral discimplant comprising: a lumen configured to be filled with the growthmatrix; and a plurality of pores that are permeable to the growthmatrix, wherein: the pores are distributed across at least one of asuperior surface and an inferior surface of the expandable pouch toprovide directional permeability of the growth matrix out of theexpandable pouch into the intervertebral disc space, and thedistribution of the pores is arranged in a gradient with the highestconcentration of pores located on the superior surface and the inferiorsurface and the concentration of pores decreases according to thegradient toward a lateral surface of the expandable pouch resulting inprovide less permeability across the lateral surfaces as compared to atleast one of the superior surface and the inferior surface; wherein thelateral surface, the superior surface, and the inferior surface are thesame dissolvable material; and wherein the intervertebral disc implantprovides flexibility to the spine where the intervertebral disc implantis placed between the superior vertebra and the inferior vertebra andafter the intervertebral disc implant is filled with the growth matrix.20. The system of claim 19, wherein the expandable pouch furthercomprises a fill port disposed through a posterior surface of theexpandable pouch, wherein the fill port provides postoperative access tothe lumen of the expandable pouch for refilling with the growth matrix.21. The system of claim 19, wherein the expandable pouch is deflatableto fit inside a surgical trocar-cannula having an inner diameter of lessthan approximately 20 millimeters.
 22. The system of claim 21, whereinthe expandable pouch is at least one of partially inflated andover-distended upon filling with the growth matrix.
 23. The system ofclaim 19, further comprising: a delivery device for surgicallyimplanting the intervertebral disc implant into the intervertebral discspace, wherein the delivery device is configured to: couple to theintervertebral disc implant, insert the intervertebral disc implant intothe intervertebral disc space from a percutaneous position, and releasethe intervertebral disc implant into the intervertebral disc space. 24.The system of claim 19, wherein the pores allow the growth matrix to atleast one of diffuse and grow from the lumen of the expandable pouch,out through the pores, and into the intervertebral disc space.
 25. Thesystem of claim 24, wherein the permeability of the pores is effected byat least one of a diameter of a plurality of pores and a chemicalstructure of the pores.
 26. A method for surgically repairing anintervertebral disc derangement in a compressed intervertebral discspace between a superior vertebra and an inferior vertebra with a growthmatrix, comprising: accessing the compressed intervertebral disc spacepercutaneously; removing at least a portion of the derangedintervertebral disc leaving an at least partially evacuatedintervertebral disc space; implanting an intervertebral disc implantcomprising an expandable pouch into the at least partially evacuatedintervertebral disc space, wherein the expandable pouch comprises: alumen configured to be filled with the growth matrix; and a plurality ofpores that are permeable to the growth matrix, wherein: the distributionof the pores provide permeability across at least one of the superiorsurface and the inferior surface of the expandable pouch, and thedistribution of the pores provide less permeability across the lateralsurfaces of the expandable pouch as compared to at least one of thesuperior surface and the inferior surface; and filling the expandablepouch with the growth matrix, wherein the intervertebral disc implantprovides movement and flexibility to the spine where the intervertebraldisc implant is placed between the superior vertebra and the inferiorvertebra and after the intervertebral disc implant is filled with thegrowth matrix.
 27. The method of claim 26, wherein the removed portionof the deranged intervertebral disc comprises at least part of thenucleus pulposus.
 28. The method of claim 26, further comprisingexpanding the compressed intervertebral disc space prior to deploymentof the intervertebral disc implant into the at least partially evacuatedintervertebral disc space.